Type-bar mechanism for typewriting machines



April 7, 1953 B. M. DANIEL 2,633,962

TYPE-BAR MECHANSM FOR TYPEWRITING MACHINES Filed Deo. 15, 1951 /NVENTOR 4BENJ/lM/N M. DAN/EL A 77' ORNE V Vprises a type bar I I pivotally mounted at Patented Apr. 7, 1953 TYPE-BAR MECHANISM FOR TYPEWRITING MACHINES Benjamin M. Daniel, Bridgeport, Conn., assgnor to Underwood Corporation, New York, N. Y., a. corporation of Delaware 'Application December 15, 1951, serial No. 261,196

2 claims. (o1. 19t-37)' This invention relates to typewriting machines and more particularly to type-bar mechanisms for such machines, especially to type-bar mechanisms of the class wherein a case-shiftable type head is mounted upon a type bar. The invention is illustrated as embodied in the well known Elliott Fisher at platen machine, suchfor eX- ample, as described in the patent to Sundstrancl No. 2,370,505.

It is an object of the present invention to provide an improved type-bar mechanism of the kind comprising a type head shiftably mounted on the outer end of a type bar.

Tt is a more specific object of the invention to provide a type-bar mechanism which constitutes an improvement overv that described in the patent to Swanson, No. 2,480,979.

lt is a further object of the invention to provide a type-bar mechanism of the kind comprising a type head shiftably mounted on the outer end of a type bar having a minimum number of parts subject to wear, and in which the weakest part may be readily replaced from time to time Without removing the type bar from the machine.

These and further objects, features and advantages will become more readliy apparent as the description of a preferred embodiment of the invention proceeds.

Referring now to the drawings:

Figure l is a view partly in side elevation and partly in section illustrating the mode of operation of the type bar of the present invention.

Figure 2 is an enlarged view partly in side ele-l vation and partly in section showing the shiftable type head locked in position to enforce the printing of one of the types,

Figure 3 is a View similar to Figure 2 and showing the shiftable type head detented in position to enforce the printing of the other of its types, and Y Figure 4 is a sectional View taken along the line i-4 of Figure 2.

In the machine described in the above mentioned `Sundstrand patent a plurality of type bars are mounted upon a semi-circular ring indicated herein at I0, forming part of the type carriage. The type-bar mechanism illustrated herein com- I2 upon a hanger I3 secured in a suitable manner to the semi-circular ring l0. An operating link tti is pivoted to the lowed end of the type bar and is selectively operable from the keyboard of the machine to swing the type bar II about its pivot I2 to imprint against a fiat platen I5. |A spring I6, operating through an arm I1 pivoted to the type bar, tends to hold said type-bar mechanism against a stop ring I8, as shown in full lines in Figure 1, and serves to return the bar to that position after each typing operation.

The upper end I9 of the type bar is flattened, and pivotally mounted upon the attened portion, by means of a pin 20, is a type head 2l. The type head is slottedto provide two legs 22 and 23 which closely embrace the flattened sides of the upper end of the type bar I0 to prevent side play of the type head with respect to the type bar. The bottom of the slot in the type head is straight as indicated at 24 to bear against a flat edge 25 of the end I9 of the type bar when the type head is in the Figure 2 position and to bear against a flat edge 26 of the end i9 when the type head is in the Figure 3 position.

An operating lever 21 is pivotally mounted between the legs 22 and 23 of the type head by means of a pin 28. The end I9 of the type bar is notched to provide a pair of surfaces 29 and 30 for cooperating with a nose 3| of the operating lever 21, and a light spring 32, extending between the type head and a free end 33 of the operating lever, holds the nose 3l of said lever against one or the other of the surfaces 29 and 30 when the type head is in an imprinting position. The surface 29 is at such an angle with respect to the pivot 20 that, when the type head is in the position shown in Figure 2, one side of the nose tI, in cooperation with the spring 32 and the surface 29, serves to lock the head in that position, which, as will be apparent from Figure 1, will cause a type 34 to strike against the platen I5 when the type bar is actuated. This locking action is brought about by the fact that attempted rotation of the type head from the Figure 2 position causes the nose 3| to exert its force along a line almost perpendicular to the surface 29. The surface 30 is sloped so that when the type head 2l is in its Figure 3 position, to locate a type 35 for imprinting against the platen, the lever 21, in cooperation with the spring 32 and surface 30, merely detents the head in this position without locking it.

Mounted in the type carriage of the machine in a suitable manner, for example as disclosed in the patent to Wise, No. 2,334,464, is a trip ring 36, selectively movable by suitable means from the normally elevated dot-and-dash line pesition to the full line position, as shown in Figure 1. With the ring 36 in its dot-and-dash line position, actuation of the type-bar mechanism causes the bar II to swing about its pivot and 3 strike the type 35 against the platen. When the trip ring 36 is moved to its full line position, actuation of the type-bar mechanism brings the free end 33 of the operating lever 2'! into contact With said ring, and continued downward movement of the type bar forces the operating lever to 'swing'A the type head 2| from the position shown in Figure 2 to the position shown in Figure 3, the lock formed by the contact of the side of the nose 3| with the surface 29 being broken by the contact of the free end` 33. o f the operating lever with the trip ring 36. When the type bar returns to its home position the free end 33 of the operating lever contaf'ztsVV the stopl ring I8 and forces the type headA Y2| to rock back from its Figure 3 position to its Figure 2 position, this movement being permitted bythe fact. that the type head is merely detented in its Figure 3 position and pressure against the free end of the lever 21 causes the nose 3| to cam off of the surface 30..

The weakest part of the present mechanism, and consequently the part which will wear out iirst, is the spring 32 and this spring; may be readily replaced without removing the type bar from the machine. This ease of servicing the present mechanism constitutes a considerable improvement over the device of the Swanson patent, No. 2,480,979, referred to above. Inthe Swanson`4 patent the lugs 83 and Q2 are subject to considerable Wear due to the reciprocating movement of the spring '18 and when these lugs become soA worn, as they do after a relatively short while, that they will not support the spring T8, it isnecessary to replace the entire type bar.

Having thus described the construction and advantages of the present invention, what is claimed is:

1. In a typewriting machine, a type bar having an end portion, a type head mounted upon said end portion and movable from a rst position to a second position, a type mounted in said type head in a position to engage a platen when said type head is in its rst position, a second type mounted in said type head in position to engage a platen when said head is in its second position, an operating lever movably mounted on said type head, resilient means urging said operating lever toward said end portion, cooperating means on the said end portion and said operating lever serving in conjunction with said resilient means to detent said type head in one of its two positions, and other cooperating means on said end 'portion and said operating lever serving;` in conjunction with said resilient means to kick-saidI type head in the other of its two positions.

2. In a typewriting machine, a type bar having an end portion, a type head pivotally mounted upon said end portion and swingable from a rst position to a second position, a type mounted in said type head in a position to engage a platen when said type head is in its rst position, a second type mounted in said type head in position to engage a platen when said head is in its second position, an operating lever pivotally connected at one end to said type head, and having a free end, a coil spring urging the free end of said operating lever toward said end portion of said type bar, cooperating means on the said end portion and said operating lever serving in conjunction with said spring to detent said type head in one of its two positions, and other cooperating means on said'. end portion and said operating lever serving in conjunction with said spring to lock said type head in the other of'its two positions.

BENJAMIN4 M. DAN IEL,

No references cited. 

